Multi server port forwarding

Everything seems to be working. I can send mail and all services seem to be working in the admin panel. The next step is figuring out how to point the ports. Any one have an idea which server needs which ports?

which round robin scenario? if you have 2 mta servers, you'd probably want to open port 25 for both, which means you'd need 2 outside ip addresses to map them to. If you don't have that then pick one or the other.